In a bowl, mix the lamb chunks with the yogurt, ground coriander, ground cumin, ground turmeric, and salt. Let it marinate for at least 1 hour, preferably longer, in the refrigerator.

Heat the oil or ghee in a large pot or Dutch oven over medium heat. Add the cinnamon stick, cardamom pods, cloves, and bay leaf. Sauté for about 1-2 minutes until the spices are fragrant.

Add the finely chopped onions to the pot and cook until they are golden brown, about 10-15 minutes. Stir occasionally to prevent burning.

Add the minced ginger and garlic to the pot and cook for another 2-3 minutes until fragrant.

Add the marinated lamb along with the yogurt mixture to the pot. Cook on medium-high heat until the lamb is browned on all sides, about 5-7 minutes.

Stir in the ground almonds or almond flour and cook for another 2-3 minutes. This will help to thicken the sauce. Then, add the heavy cream and mix well.

Reduce the heat to low, cover the pot, and let the korma simmer gently for about 1.5 to 2 hours, or until the lamb is tender and the flavors have melded together. Stir occasionally and add a bit of water if the sauce becomes too thick.

Stir in the garam masala and ground red chili. Adjust the seasoning with salt if needed. Let it cook for another 5 minutes.

Remove the whole spices (cinnamon stick, cardamom pods, cloves, and bay leaf) before serving. Garnish with chopped fresh cilantro and sliced almonds if using.

Serve the Lamb Korma hot with basmati rice, naan, or roti.